Note: Descriptions are shown in the official language in which they were submitted.
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1 YIELD OF THE INVENTION:
The invention relates to a handheld or portable planer,
having a planing head driven by an electric motor mounted
in a housing. The planing head is rotatable mounted in
the same housing as the motor. The planer further come
proses a blower attached to the electric motor for pro-
during a motor cooling air stream, and a chip ejection
channel in the housing to which the motor cooling air
stream may be guided through a connecting channel.
DESCRIPTION OF THE PRIOR ART:
Such a portable planer is Cole from German Utility Model
Publication 7,812,329 wherein most of the cooling air
stream is directed to the chip ejection channel for blow-
in out the chips and shavings, whereby a high kinetic
energy is imparted to the chips in addition to the chip
velocity imparted by the planing head. This high kinetic
energy may cause the chips to wedge and lodge against each
other, thereby clogging the chip ejection channel. Further-
more, the chips can only be expelled from the chip eject
lion channel from one side of the tool. Therefore, uncertain operating positions, the ejected chips will nieces-
sanity strike the operator, thereby becoming an annoyance
and an inconvenience.
OBJECTS OF THE INVENTION:
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In view of the above it is the aim of the invention to achieve the following objects singly or in combination:
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1 to provide a portable planer of the type desk
cried above, in which the chips may be effectively ox-
polled from the chip ejection channel, without becoming
lodged in the ejection channel and to avoid clogging of
the ejection channel;
to provide such a planer with an adjustable
chip ejection channel, so that chips may be expelled
from either side of the tool housing as desired, for
greater safety and convenience of the operator;
to provide such a planer with a means for ad-
jutting the chip ejection air flow, so that the Advent-
genus characteristics may be maximized under various
operating conditions; and
to direct the chip ejection air stream in such
a planer so that it simultaneously achieves a drive belt
cooling effect for the planing head drive belt.
Clime
These objects have been achieved in a portable planer
according to the invention, by an air stream connecting
channel comprising a branch duct through which only a
small portion of the total motor cooling air volume is
directed into the chip ejection channel. Tests have shown
surprisingly, that a satisfactory ejection of the chips
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1 out of the tool can be assured with only a relatively
small portion of the motor cooling air being directed
into the chip ejection channel. Thus, with this reduced
air flow, the chips do not become wedged or lodged against
each other, and they may effectively be expelled from
the tool under all operating conditions. According to
the invention the branched off air flow acts as a loosening
means for the chips.
This becomes especially advantageous when a pivotal damper-
type deflection flap is operatively mounted in the chip
ejection channel. The expelled chip stream may be directed
to either side of the tool as desired, by means of this de-
election flap. For this purpose, the tool housing has chip
exits on both sides. The observed effectiveness is maxim
mixed when the opening for the air stream is located below
the bottom or lower end of the deflection flap when it is
pivoted to eject chips on the side of the tool opposite
the air stream opening. However, a considerable improve-
mint in chip ejection is also achieved, even if the de-
election flap of such a planer having an air stream
opening only on one side is pivoted so as to eject chips
on the same side as the air stream opening.
Preferably, one air stream opening is provided on each side
of the housing, to achieve an optimal chip ejection to
either side of the machine as desired. Also by adjusting
a control or adjustment element in the connecting channel,
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1 it is possible to adjust or match the branched off air
flow to the existing operating conditions.
A further advantage is achieved in that the hollow chamber
which acts as the connecting channel also houses the plan-
in head and the drive belt for the planing head, where-
by the air stream will serve for chip ejection and for
cooling the drive belt and the planing head. The air flow
for chip ejection is sufficient to cool the belt, and will
remain constant since the air flow passages will not become
clogged or obstructed by chips and shavings.
BRIEF DESCRIPTION OF THE DRAWING-
In order that the invention may be clearly understood, it
will now be described, by way of example, with reference
to the accompanying drawings, wherein:
Fig. 1 shows a portable planer in a view
from the drive belt side, with the
side cover removed; and
Fig. 2 is a sectional view along section
line II - II in Fig. 1.
DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND
OF THE BEST MODE OF THE INVENTION:
An electric motor 2, which is arranged in a housing 1 of
the portable planer, drives the planing head 4 by means of
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1 a belt 3. The chips and shavings removed from the work
piece by the planing head 4 pass upwards through a chip
ejection channel 5 and out of the tool. For this pun-
pose, the housing 1 has a lateral opening as best seen
in Fig. 2.
.
A deflection flap 6 is pivotal mounted on an Essex-
tidally horizontal axis 6' in the chip ejection channel 5.
The flap 6 may have reinforcing ribs 6". By manually pivot-
in this deflection flap 6 as desired either into the full
line position or into the dash-dotted position the chip
stream may be directed out of the housing on the left or
right side thereof, as seen in Fig. 2.
A blower 7 draws cooling air axially through the motor 2,
and then exhausts most of this cooling air stream to the
outside of the tool through slots 8. However, a window
or port I is provided in a side wall 9 of the housing 1
for passing a small portion of the motor cooling air stream
through the port 10 into the chamber 11 which houses the
planing head 4 and the drive belt 3 for the planing head.
The chamber 11 is enclosed by a hood or cover 12, see
Fig. 2. The air stream through the window 10 thus serves
to cool the drive belt 3 and planing head 4. The chamber 11
then extends to directly below the chip ejection channel 5
and is connected thereto through an air stream opening 13
which leads at an angle upwards as best seen in Fig. 2
as
1 If the deflection flap 6 is in a position as shown by
solid lines in Fig. I then the opening 13 opens directly
under the lower end of the deflection flap 6, whereby
the angle of inclination of the opening 13 substantially
corresponds to the angle of inclination of the flap I
thereby forming an extension of the deflection flap 6. The
redirected or branched-off portion of the cooling air
is thus guided along the deflection flap 6 and achieves
a trouble-free ejection of the chips which are entrained
in this air stream.
Even if the deflection flap 6 is in a position shown by
dash-dotted lines in Fig. I the branched-off cooling
air stream can still maintain such a chip ejecting air
flow in the chip ejection channel 5 so that the chips may
be effectively ejected rather than compacted and jammed
as in the prior art.
In order to further improve this chip loosening effect
a second opening 13' may be provided on the opposite side
of the chip ejection channel 5 as shown in the left side by
dash-dotted lines in Fig. 2. This second opening 13' is
located substantially opposite the first opening 13.
In order to control or adjust the branched-off air stream
through the window or port 10 for various operating condo-
lions, an adjustment element in the form of a slider gate 14
is provided for the window or port 10. This slider gate 1
may be manually adjusted as indicated by the arrow Lowe
the operator, whereby the port 10 is opened to a lesser or
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1 greater extent in order to regulate the volume of air
flow which is branched-off through the chamber 11 to the
chip ejection channel 5.
The most advantageous chip ejection air volume has been
found to be 5 - 10% of the total motor cooling air volume.
However, under certain operating conditions, the chip
ejection air flow may be adjusted to account for up to
30% of the motor cooling flow.
Although the invention has been described with reference
to specific example embodiments, it is to be understood
that it is intended to cover all modifications and
equivalents within the scope of the appended claims.
